SPI speed

[zoltanszalontay]

Is there any way to set the speed of the SPI bus?

I am using lepton3-dev with an RPI 3B+ and a 4B with a Lepton 3.5 via a Breakout Board v2. I set the CPU governor to run at fixed 100%. Video is fine, but there are sporadic lost frames ("Garbage..." message). Also, when I start picamera, the pylepton almost stops. As soon as I stop picamera, Lepton capture gets smooth again. (OK, that may be because the two I/O operations are blocking each other so threading should be used.)

I suspect the SPI bus speed is slow by default because when I used flirpy with my PureThermal, I could get stable video without any errors at 30MHz only. Anything below that caused split frames or garbage.

I am aware that pylepton does not use I2C, but I hope basic SPI settings, like bus speed can be configured. As I see, it is done via ioctl, but could someone help me where exactly?

[zoltanszalontay]

I did not debug it yet, but anyone knows if I can set SPI speed here?

pylepton/pylepton/Lepton.py

Line 23 in c856c6a

SPI_IOC_RD_MAX_SPEED_HZ = _IOR(SPI_IOC_MAGIC, 4, "=I")

[arushk1]

Hi @zoltanszalontay I'm facing the same issue. You can set the SPI bus speed at Line 46 in Lepton.py :

SPEED = 18000000

Setting the speed does not do anything to smooth out the video. It's bad when using the PiCamera simultaneously.

Even threading does not help. Running them in the two different processes does not help.